Railway signaling



CHARLES W. IDUNI-IAM, 'OF FAIR/MONT, PENNSYLVANIA, ASSIGNOR' TO UNION SWITCH &; SIGNAL COMPANY, F SWISSVALE, PENNSYLVANIA, A CORPORATION l OF PENNSYLVANIA. y

RAILWAY SIG-NALING.

Application filed December 27,1919. Serial No. 347,748. Y

y To all wit-omit may concern Be itknown that I, CHARLES W.V DUNHAM, a citizen of the United States, residing at Fairmont, inthe county of Westmoreland and lState of Pennsylvania, have invented certain new and useful Improvements in Railway Signaling, of which the following is a specication.l y

My invention relates Vto 'electrical apparatus, and particularly to apparatus comprising a polarized relay, a circuit for such relayincluding a-,source of current`and a pole-changer, and a second circuit controlled by the polarized relay.

One object of my invention is the provision of a novel means for reducing the interval of time during which the second circuit is open while the polarized relay is responding to a reversal of the pole-changer.

Apparatus embodying my invention is particularly well adapted to the control of signals and otherdevices for governing the passage of cars and trains along a railway, although it is not limited to such adaptation.

' I will describe one form and arrangement of apparatus embodying my invention, and will thenpoint out the novel features thereof in claims.

The accompanying drawing is a diagrammatic view showing a railway signaling system including a signal controlled in accordance with one form of my invention.

Referring now to the drawing, the reference characters 2 and 2a designate the track rails of a railway over which traffic normally moves in the direction indicated by the arrow. The rails are divided by insulated joints 3 into a plurality of sections of whichonly one complete section A- B is shown in the drawing. The section A-B is provided with a track circuit comprising as usual the track rails of the section, a loattery 5 connected across the rails at the exit end of the section, and a track relay 6 connected across the rails at the entrance end of the section.

Located adjacent the entrance end of the section A-B, is a signal SB governing traffic through this section. This signal is controlled by a polarized relay R which, in turn, is controlled by the track relay 6 and by a pole-changer P operated by a signal SA at the entrance end .of the section tothe left of section AV-B. The circuit for relay R is from a battery CA, through wire 7, polechanger P,.wire8, contact 9 oftrack relay l i 6,v wires 10 and 10a, winding ofrelay R, wires l1a and 11, pole-changer Pand wire 12 to battery CA. When signal SA is in the stop position, the polarity ofthe current supplied to relay R by battery CA is such that polarized contact 32 of,V this relay is open, and this currentI will term current of reverse polarity. When signalv SA is in/ the caution or proceed position, the pole-changer P is in the opposite position, so that current of normal polarity is supplied to relay R and contact 32 of this relay then becomes closed. Obviously, when track relay 6 -is open, as shown in the drawing, relay R is denergized, so that the frontV points of its neutral contacts 15 and 24 are open and the back points of these contacts are closed. v

The signal SB comprises a semaphore 4 biased to the horizontal or stop position, an electric motor. M for moving the semaphore to the inclined or caution position andv to the vertical or proceed position, anda holding magnet H for holding the semaphore in the two last-mentioned positions. l

As shown -in the drawing, section is occupied by a car or train V, so that track relay 6 is open and polarized relay R is deenergized. All circuits for the control of motor M and holding magnet I-I are, consequently, open so that the semaphore 4 of signal SB is in the stop position. I will now assume that the car or train V passes` out of section A-B and into the section next to the left. Track relay 6 then closes and signal SA moves tothe stop position, so that current of reverse polarity is supplied to relay R. The neutral front contacts of this relay then close, but the polarized contact 32 opens. Holding magnet I-I then becomes energized, the circuit being from battery CB, throughvwire "14, front point .ofv contact 15 of relay R, wires 16, 17 and 18, contact; 19a- 19 operated by semaphore 4, wire 20, winding of magnet H, wire 21, Contact 22 of track relay 6, wire 23, front point of contact 24, and wires 25 and26to battery CB. TheV operating motor M lis also energized,

the circuit being from battery CB, through wire 14,y front point of contact'l, wires 16, 17 and 27, contact 28-28, wire 29, motor M and wires 8O and 26 to battery CB. Motor M then operates to move semaphore 4 to its inclined or caution position at which point the circuit just traced for the motor is opened, because the wiper 28 passes oil' oi contact Segment 28u. The signal is held in the caution position by magnet H,however, because wiper 19 still engages with contact segment 19.

When the car or train passes out or the section to the left of the section A-B, signal SA will move to the caution position, thereby shifting` pole-changer P, so that current of normal polarity will be supplied te the polarized relay R. Contact 32 of this relay then closes and the iront points of the neutral contacts open momentarily, but `for the present I Vwill assume that this openingof the neutral'front contacts does not cause magnet H to release the semaphorel 4. A new circuit for motor M is then closed, which circuit is from battery CB, through wire 14, front point or' contact 15, wires 16 and 81, ypolarized contact 82,7wires 88 and 35, contactv 28b'-28, wire 29, motor M and wires 30 and 26 to battery CB. Motor M then operates to move thesemaphore toward the proceed position, magnet H beingenergized during the first part of such movement by the same circuit as before, that is, through contact 19-192. After the semaphore has moved a short distance, however, contact 19-19) closes and contact 1919a opens, whereupon anew circuit for magnet H closes, passing` from battery CB through wire 14, front point oi' contact 15, wires 16 and 31, contact 32, wires 33 and 34, contact 19h- 19, wire 20,'magnet H, wire 21, contact V22, wire 28, front point of contact 24, Vand wires 25 and 26 'to battery CB. When the semaphore reaches the proceedvposition, the wiper 28 passes off of the contact segment 28h, so that the motor stops.` rl`he signal is held in this position Vby magnet H, however, because wiper 19 still engages withl the Y yturns to the stopposition Y 'As I have already pointed out, when sig# contact segment 19". f l Y y When signal S13-is in the proceed or caution position and a car or train enters section A-B, the opening,r of track relay 6 causes the polarized relay R to be deenergized, so that all circuits for motor W and holding` man'n net H become opened and signal SB then renal SB is-in the caution position and the polarity of the current supplied tothe Vpolarized relay Ris reversed, the iront points vof neutralcontacts 15 and 24 are momentarily opened, and this action will cause magnet H to release the semaphore unless means are provided to prevent such action. As here shown, this is prevented by supplying current to magnet H from battery CA while the back points of contactsl and 24 are closed during the reversal of polarity. As* suming` that signalSB is in the caution position, and that pole-changer P reverses, the circuit for holding magnet Irl duringthe brietinterval or time that the back con'- tacts of relay R are closed, is from battery CA, through wire 7, pole-changer P, wire 8, track relay contact 9, wires 10 and 36, back point of contact 24, wire 23, track relay contact 22, wire 21, magnet H, wire 20, contact 19-19, wires 18, 17 Vand 16, back point of contact 15, wires 37 and 11, pole-changer P, and wire 12 to Vbattery CA. lt is, oi' course, understood that when pole-changer P reverses, the interval ot time during which the circuit for relay H is open is very short, in lact only a small fraction of a second. lt is also well understood that the characteristics ot relay P and of the circuit in which it is included are such that when the polelchanger reverses, the time-interval required for the back contacts ot relay' R toV close is substantially the same as the time interval during' which the circuit is open at the pole-changer.Y It follows, therefore,

that when the pole-changer reverses, the back points o1 contacts 15 and 24 will close at substantially the instant the circuit is reclosed at the pole-changer, and so magnet H Ynot depend upon the front 'contacts-otV the polarized V relay R being open for la brief period of time, it is obvious that it is possible to make this relay slow-acting'. As is well understood a relay of this character Vis desirable in signalingsystems oit certain types,

such, for example, as that known as absolute permissive block signaling. Y Y

t will be observed that the circuits `for theholdiug magnet VH pass through a contact of the track relay- 6. The reason for this is to make the signal respond quickly when a train enters the section AHB. This is particularly desirable in the event that `the polarized relay R is slow-acting. It will be seen, therefore, that'by my invention I am y enabled to retain allot theadvantag'es oi a signal with a quick-jacting-holding magnet and still eliminate the bobbingVat'caution and proceed positions and Vother objection- Yable features which have u'suedlyv required a slow-acting holdingA magnet,

One important feature of my invention is that the desired resultY is accomplished without any additional circuit breakersupon the signal or the controlling relay through which the motor current must pass.

4Although I have herein shown and described-only one form and arrangement of apparatus embodying my invention, itY is understoodthat various changes and modifications may be made therein withinthe scope of the appended claims without departing lfrom the spirit and scope of my invention.

Having thus described my invention, what I claim is: f

l. In combination, a circuitv including a relay 'having iront and back contacts, a source of current, and lmeans for reversing the polarity of the current supplied to said relayv by said source; a signal including a Y biased semaphore and a magnet for holding the semaphore against the biasing force, a second source of current, and means for supplying said magnet with current from said second source when the front contacts of said relay are closed and from said irst source when the back contacts of the, relay are closed. i

r2. In combination, a circuit including a relay having front and back contacts, aV

source of current, and means for reversing the polarity of the-current supplied `to said relay by said source; a signal including a biased semaphore and a magnet for holding the semaphoreagainst the biasing force,V a second source of. current,*and means controlled by the contacts of'said relay for connecting said magnet with said second source of current when the front contacts are closed and for .connecting said magnet with said circuit in multiple with said relay when theback contacts are closed. Y

3. In combination, acircuit including a relay having front and back contacts, a source of current, and means for reversing the polarity of the current supplied to said relay from said source; a second source of current, a signal, and means for supplying said signal with current from said second source when the front contacts of said relay are closed and from the first source when the back contacts of said relay are closed.

4L. In combination, a section of railway track, a track circuit for said section, a line relay having front and back contacts, a line circuit controlled by said track circuit and including said line relay and a source of current, means controlled by traffic conditions in advance of said section for reversing the polarity of the current supplied to said line circuit by said source, a signal for said section, a local source of current for said signal, and means for connecting said signal with said local source when the front con- @acts @t `Said 1in@ relay are closed and with said line circuit yin multiple with said line relay when the back contacts of the line relay are closed.-

5. In combination, a section of railway track, a track circuit for said section, a line relay having front and back contacts, a line circuitcontrolled by said track circuit and including said line relay and a source of -current, means controlled by traffic .conditions in advance of said section ,for reversing the polarity orp the current supplied to said line circuit by said source, a signal for said section including a biased semaphore and a magnet for holding said semaphore against the biasing force, a local source of current forsaid signal, and means for connecting said magnet with said local source when the. front contacts of said line relay are closed and with said line circuit in multiple with said line relay when the back contacts of the line relay are closed.

6. In combination` a section of railway track, a track circuit for said section including a track relay, a line relay having Jiront and back contacts, a line circuit controlled by said track relay and including said line relay and a source oit' current, means controlled by traiiic'conditions lin advance of said section for reversing the polarity of the current supplied to said line circuit by said source, a signal for said section including a biased semaphore and a magnet for holding the semaphore against the biasing force, a local source of current for said signal, a circuit for said magnet including said local source of current and the front contacts of said line relay, anda second circuit for said'magnet including the first-mentioned source of current and a 'front contact of said track relay and the back contacts of said line relay.

7. In combination, a section of railway track, a track circuit for said section including a track relay, a line relay having front and back contacts, a line circuit controlled by said track relay and including said line relay and a source of current, means controlled by traiiic conditions in advance of said section :tor reversing the polarity of the current supplie-d to said line circuit by said source, a signal for said section including a biased semaphore and a magnet for holding the semaphore in opposition to the biasing force, a local source of current, a circuit for said magnet controlled by the front contacts v of said line relay and a front contact of said track relay and including said local source of current, and means for connecting said magnet with said line circuit in multiple with said line relay when the back contacts of the line relay are closed.

8. In combination, a circuit including a relay having front and back contacts, a source of current, and means for reversing the polarity of the current supplied to said relay from said source, a second source of current, a signal, a circuit for said signal including said second source of current and the front contacts of said relay, and a second circuit for said signal including the rst source of current and the back contacts of said relay. y n

9. In combination, a circuit including a relay having front and back contacts, a source of current, and means for reversing the polarity of the current supplied to said relay by said source; a signalv including a biased semaphore and a magnet i'or holding` the semaphore against the biasing force, a second source of current, a circuit for said magnet including said second source of current and the front contacts of said relay, and

' a second circuit Jfor said magnet including said first source of current and the back contacts of said relay.

l0. In combination, a circuit including a relay having front and back contacts, a source of current, and means for reversing the polarity of the current supplied to said relay from said source; a second source of current, a signal including a semaphore biased to one position, a motor forV moving it to another position, and a magnet for holding the semaphore in the latter position; a circuit for said motor controlled by thev front contacts of said relay, and means for supplying said magnet With current from said second source When the front contacts of said relay are closed and with current from said :[irst source when the front contacts of said relay are open.

11. In combination, a relay having front and back contacts, a circuit for said relay including aV source of current and a polechanger, a second circuit controlled by said relay, a second source of current, and means for supplying current to said second circuit from said second source When the front contacts of said relay are closed and from said first source when the back contacts are closed.l

, 12. In combination, a `relay having front and back contacts, a circuit for said relay including a source of current and a polechanger, a magnet, a second source of current, a circuit for said magnet including said second sourceand the front contacts of said relay, and a second circuit for said magnet including the first source of current and the back contacts of said relay.

13. In combination, a relay having front andbaclr contacts, a circuit `for said relay including a source ofv current and a polechanger, the elements'in said circuit being so arranged and adjusted that when the pole- CHARLES W. DUNHAM.A Y .l/Vitnesses A.`IIERMAN VVEGNER, C. S. SNAVELY. 

